Aqueous gel materials have been widely used in medicines, medical instruments, medicinal materials, cosmetics, living sundries, architectural materials, paints, chemicals, photos and so forth. They include such raw material as an aqueous synthetic polymer and a natural polymer. Typical aqueous synthetic polymers include polyvinyl alcohol, and cross-linked sodium polyacrylate.
On the other hand, typical natural polymers include agar, carrageenan, gelatin, and gellan gum, which have been subjected to trial applications in foods as natural polysaccharides to form aqueous compositions having viscosity or viscoelasticity. Such the polysaccharides have also been blended in fragrances, and deodorants, and also utilized as gelling agents (see Patent Document 1, Patent Document 2, Patent Document 3 and Patent Document 4).
These days, in relation to problems of wastes loaded on environments, materials with merits, such as material biodegradable after disposal and material processable by recycling, have been developed. In general, polymeric agent materials such as polymers of lactic acid and amino acid have been developed as the biodegradable material, and utilization of polyethylene terephthalate (PET) has proceeded in terms of recycling.
Available water-containing materials include various gelling agents, typically polyvinyl alcohol, and cross-linked sodium polyacrylate. Among those, natural materials are particularly advantageous and significant in environmental issues because of biodegradation on disposal and safety to human. They are materials having wide versatility and available with safety in any industrial fields without consideration of loads on environments, such as disposed water, disposed gases and disposed solvents resulted from chemical synthesis.
Patent Document 1: JP 61-185541 A
Patent Document 2: JP 1-40542 A
Patent Document 3: JP 1-74239 A
Patent Document 4: JP 10-248505 A